My boiler has low pressure

In the event of the boiler indicating a low water pressure fault the heating system can be topped up by opening the heating system fill valves located beside the hot water tank in the hot press. There will be a label located on the tank indicating the valve. The black levers on the valve need to be both open to top the system back up to 1.5 Bar on the gauge located on the gas boiler on the ground floor. Once this is achieved make sure to fully close the both valves so that they are situated across the pipe not in line with the pipe. Please carry out this procedure slowly so as to prevent the pressure going up too high on the system.